FR2619661A1 - PLAYER OF VIDEO IMAGE PRESENTATIONS TO SUBSCRIBERS IN A DIGITAL INTERACTIVE COMMUNICATION SYSTEM - Google Patents

Abstract

The presentation player 54 is used in a digital interactive communication system, accessible to a multiplicity of subscribers who can choose from a multiplicity of prerecorded video / audio presentations to watch on their television set. It comprises a converter 66 which is tuned on a channel, for monitoring a stream of digital information containing packets of digital bits representative of the video / audio presentations chosen by the subscribers. These digital bit packets contain an address assigned to the particular requesting subscriber and processed by a control unit 64 which distributes the digital bit information packet to one of several subscriber servers 62 housed in the presentation player. .

Description

The present invention generally relates to systems of

  digital interactive communication, capable of transmitting, at the request of a subscriber, television video still images, possibly with an accompanying audio message, and more particularly a presentation reader which receives a train of digital bit packets by a link of standard standard antenna television distribution, converts the digital bit packets into the selected video presentation, with an accompanying audio message, and transmits this presentation to the subscriber who requests it, on a pre-assigned output channel in a broadcast distribution system. standard collective antenna television. Conventionally, different types of communication systems are used to provide subscribers with voice, data and video communication services. In particular, interactive cable television systems have been developed for distributing information to subscriber television sets at their request. One of these systems is a shopping service, with subscribers shopping at home in an "electronic shopping mall". This system differs from home shopping channels in that it allows subscribers to choose the products or services they will be viewing on their television screen, using a home-based subscriber device, such as a telephonic station or a group antenna television keypad. In use, the subscriber sets his station on a channel and requests its connection to a remote center by dialing a predetermined telephone number or access to the system via a collective antenna television return channel. As soon as the system has identified the subscriber, the television screen of the subscriber starts to display still video images, possibly accompanied by audio messages, and directories of "electronic shops" including products or services that are may appear or scroll, examine in more detail, save for later review or purchase, simply by pressing keys on a keypad in response to messages

  invitation on the television screen. A computer-

  central server controls the flow of information

in the system.

  This purchasing service uses a community antenna television network to distribute video presentations and accompanying audio messages requested by subscribers. At different points in the community antenna television network, a device known as an image memory unit captures the video and audio portions of a presentation. Each of these points serves a small group of subscribers. The function of each image memory unit is to capture the video images intended for

  to subscribers assigned to this image memory unit.

  The image memory unit captures a video image that carries the address of an assigned subscriber and converts it into a form that it can memorize. Then, the image memory unit determines which audio message is to be associated with the video image, groups the audio and video signals by time multiplexing the video signals on one channel, and frequency multiplexing the audio signals on a single channel. another channel, then it injects the result into the power cable of the television network by collective antenna. The composite signal emitted by the image memory unit appears as an image of

  standard television on the subscriber's station.

  The audio and video signals processed by the image memory unit are in analog format. This is in sharp contrast with the presentation player of the present invention which receives and processes in digital format, both the video portion and the audio portion of a presentation. In addition, the presentation player multiplexes both video and audio parts over time

on a single channel.

  The benefits of the presentation reader on the image memory unit are numerous. The presentation reader places the interactive communication system in a position to serve more subscribers than the prior system, in that the audio and video signals are both multiplexed over time on a single channel. In addition, digital processing of these signals results in improved distortion immunity, improved audio fidelity, and improved ability to maintain the integrity of the video portion of a presentation. An additional benefit of digital processing is an increase in the portion of the collective antenna television network spectrum usable for service transmission

proposed audio / video.

  Thus, the digital processing and time multiplexing of both the audio and the video signal by the presentation reader offer significant advantages over the image memory unit that is used in other video storage systems. interactive communication. The purpose of the present invention is to overcome the above-mentioned loopholes of the state of the art by producing a presentation reader that can be used in a digital interactive communication system capable of transmitting fixed video presentations to subscribers, video presentations. animees having the quality of television, with

accompanying audio messages.

  Another purpose of the presentation reader of the present invention is to process signals, both video and audio, in a digital format and to provide

  thus a more exact reproduction of the original signals.

  Still another object of the present invention is to exploit the presentation reader as part of a new and improved interactive communication system for merchandising products and services to subscribers. The present invention relates to a presentation reader used in an interactive communication system in which subscribers make a choice among a multiplicity of video / audio presentations to watch them on their television set. The video / audio presentations are transmitted in the form of packets of digital information bits to several presentation readers placed at strategic points in the vicinity of the subscriber. Each of the digitized bit packets transmitted to the presentation readers is

  addressed uniquely to a subscriber who makes a request.

  The presentation reader contains a converter, a control unit and at least one subscriber server. The converter is tuned to a fixed frequency narrowband control channel which broadcasts tuning information. This tuning information causes the converter to tune into a broadband channel, where it monitors a digital stream of information containing the digital bit packets representative of selected video / audio presentations. The converter also detects, for the purpose of further processing, the digital bit packets uniquely addressed to subscribers

  predetermines among those who make requests.

  The control means receives from the converter the uniquely addressed digital bit packets and transmits each of these bit packets to a pre-assigned subscriber server, according to the unambiguous address of the bit packets. That is, each presentation reader processes packets of digital bits addressed to particular subscribers. More precisely, each subscriber server in a presentation reader is in turn responsible for processing the digital bit packets of certain subscribers. The subscriber server receives the digital bit packets, converts them into analog video / audio presentations (conventional N.T.S.C system) which are then transmitted

to the subscriber making a request.

  To better understand the nature and goals of

  the invention, reference is made to the detailed description

  following, taken in conjunction with the drawings below.

attached.

  Fig. 1 is a block diagram of a digital interactive communication system which, together with a collective antenna television network and presentation reader of the present invention, provides subscribers with fixed video presentations of

the quality of the television.

  Fig. 2 is an exploded block diagram of the reader

  of presentations shown in fig. 1.

  Fig. 3 is an exploded block diagram of the presentation reader converter shown in FIG.

fig. 2.

  Fig. 4 is an exploded block diagram of the server

  subscriber shown in FIG. 2.

  Referring to FIG. 1, the presentation reader of the present invention is used in conjunction with the digital interactive system of

  cable television, designated overall by 10.

  When the system 10 is in use, a subscriber uses a keypad 12 to communicate with the system 10. The transmission signals transmitted by means of the telephone 12 are routed, on conventional telephone lines, to a local operator center ( "COL") 11 of the system 10, which applies LAN technology. At COL 11, the tone signals of the telephone set 12 are received by a voice network interface ("VRI") 14. If the tone signals are conventional voice-frequency transmissions, they are transmitted to the IRV 14 in format analog and are recognized and decoded by the IRV 14 which transforms them into ASCII characters recognized by an interface 16. In the case where the tone signals are received by the IRV 14 in the form of digital signals, the IRV 14 transforms even the keyboard signals digitized into a protocol recognized by the interface 16. The IRV 14 may be a "Specialty Digital Switch" type No. SDS-1000 "Summa Four, Inc.", comprising a predetermined number of telephone lines to divert if necessary to incoming caller service agents. Whether the tone signals are in digital form or in analog form, the output signal of the IRV is transmitted to a first local area network ("RZL") 18 via the interface 16. In FIG. 1, the IRV 14 is shown as being located at the COL 11, but it is provided by the present invention that the IRV 14 is possibly not arranged at the same place as the COL 11.

  The network topology of the first RZL 18, that is,

  say the physical organization of the network, is known as ring topology. In a ring topology, all network devices are connected by a single communication cable that forms a circle or ring. Signals are sent from one device to another around the ring. While a signal is circulating around the ring, each device of the RZL electronically detects if the message is intended for it. If so, the device processes the signal. If this is not the case, the device normally recreates the signal and

  transmits it to the next device of the ring ..

  Network access identifies the procedures that allow each device in the network to communicate and receive data. The L network access method used in RZL 18 is conventionally known as the Token Ring. A token is a special binary profile that constantly travels the network. Each device in the network must wait to receive the token before being able to transmit a message; it reinserts L5 then the token in the network, so that it is transmitted to the next device of the network. If a device does not have a message to send, it leaves the Token to go to the next device on the network. In fact, possession of

  Token is permission to transmit a message.

  The transmission medium that connects the devices in the RZL 18 is preferably a coaxial broadband or baseband cable. A base-band coaxial cable carries a single signal at a time, but the signal travels at a fast rate - in the order of 10 million bits per second. Any one of several conventional methods is applied to allow many devices to access

simultaneously with RZL 18.

  The devices comprising the RZL 18 include a plurality of single-plate computers, each of which has a special function in subscriber service, as well as random access memory, a clock, and input / output means. The single-plate computers each contain specialized application software and are each associated with an interface that connects them to the RZL 18. In addition to the single-plate computers, the RZL 18 includes a high-power database.

  28, classically referred to as "discotheque".

  In the hard disk memory units of the database are stored digital information representing video presentations of goods or services. Typically, these video presentations include still images of television quality, text information, text overlaying a still image, or any combination of these presentations. These video presentations may be accompanied by an audio message and are referred to hereinafter as "video / audio presentations". Any of these stored video / audio presentations may be viewed by a subscriber, at the request of the subscriber, during any session on the system 10. In the database 28 are also stored navigation information describing the routes between presentations, as well as subscriber information. Typically, companies (hereinafter referred to as providers) that offer goods or services to subscribers develop a video / audio presentation structure representing an electronic store. Examples of single-plate computers connected to the RZL 18 include those manufactured by "Intel Corporation, Santa Clara, California" under the type designation No. iSBC 36/100 or type No. iSBC 186/100. The computers are named after their functional application in the RZL 18 and are identified in FIG. 1 as session server 20, navigation server 22, subscriber server 24 and cashier server 26. The servers 20, 22, 24 and 26 are each identified by a single functional task, but the present invention provides that each server may have appropriate software allowing it to switch from one function to the other according to the requests of the system 10. During a subscriber session on the system 10, one of the session servers 20 will be devoted to the service of a particular subscriber . The number of session servers 20 in a COL 11 will depend on the number of subscribers served by this COL 11. Therefore, the number of session servers 20 in a COL 11 may vary between 100 and 2000 units. The output message of the IRV 14 is transmitted, via the interface 16, to one of the multiple LO session servers 20. The interface 16 associates a subscriber call that arrives at a server Session 20 available. The session server 20, as well as all the servers constituting the RZL 18, is itself connected to the RZL 18 by means of an interface. From what is L5 shown in FIG. 1, each server is connected to an interface, but it is possible, in the hardware construction of the RZL 18, that several servers share

an interface.

  The session server 20 processes the message by translating or converting it into a logical signal that other servers understand, and then transmits the signal to the RZL 18 for further processing by the other servers. Essentially, the session server 20 interprets the digital signal representing a key on the keypad 12 and sends a command or commands to other servers on the RZL 18. In these commands are contained the requests for selected presentations, made by the subscriber. The navigation server 22 contains a dynamic random access memory which can store sufficient information to allow the subscriber to browse any of the provider presentation structures. The information stored in the navigation server 22 defines the paths between the presentations in a presentation structure. By the fact that the navigation server 22 contains a dynamic memory with selective access, it will store only the navigation information that is

  useful at a particular point in a subscriber session.

  Typically, the random access dynamic memory of the navigation server 22 has approximately 10 megabytes of random access memory. The navigation server 22 is therefore not capable of storing all the presentation networks of the suppliers in its memory. This information is stored in the memories

  hard disk of the database 28.

  When the system 10 is in use, the subscriber designates the presentation or the presentations that he wants to examine by pressing keys on the telephone with keyboard 12. The digitized signals which represent the pressed keys of the telephone are processed by the server Session 20 and are addressed to the navigation server 22. The navigation server 22 searches the database 28 for navigational data that is required at this time to browse a presentation network in accordance with the subscriber's requests. Thus, when the subscriber, for example, requests information contained in a particular presentation structure, the dynamic memory will store only the navigation information relating to the part of the presentation network that could be requested by the subscriber at this particular moment. of the subscriber session. As the session proceeds and the subscriber goes through the presentation structure, the navigation information contained in the dynamic memory will change with the subscriber's course in the structure. According to this navigation data stored in its dynamic memory and according to its interpretation of the digitized signals of the session server 20, the navigation server 22 determines which of the presentations stored in the database of the data 28 have been selected by the user. subscriber and it sends a signal, by the RZL 18, so that the database 28 transmits the requested presentations to the subscriber. The subscriber information server 24 stores

  information about the subscribers of the system 10.

  The stored information about each subscriber includes the subscriber's telephone number, the subscriber's personal identification number, and identifies a presentation reader designated to receive the subscriber's requested submissions. As will be explained in more detail below, the presentation reader receives, stores and retransmits to

  the subscriber the presentations requested by him.

  Typically, the server 24 is active only during part of a subscriber session. When the system 10 is in use, the session server 20 requests the subscriber server 24 for information concerning a subscriber. The server 24 then searches for the requested information and sends it to the session server 20 which stores it in its memory. By the fact that the session server 20 is active throughout the subscriber session, there will be no need to ask the subscriber server 24 for other information during the rest of the session.

of the subscriber.

  The cashier server 26 processes all the information concerning the purchase of goods or services by the subscriber. For example, the cashier server 26 asks the subscriber by which means he intends to pay for his purchases. If the subscriber chooses a credit card as a means of payment, the cashier server 26 obtains in the database 28 the identification number of the credit card of the subscriber and sends an appropriate message to a customer service department. authorization, so that the amount of the purchase is charged to the subscriber's credit card. Another function of the cashier server 26 is to notify the suppliers of the purchases made, so that the goods are dispatched quickly.

to the subscriber.

  Purchase information may be transmitted directly to the vendor or it may be stored in the cashier server 26 and "batched" to a vendor at a later time. For example, all the purchases made during a given period are stored by the cashier server 26 in a data storage file, but they are sent in batches, at the end of the period, to the various suppliers for these to give them. after. The cashier server 26 may also describe the means by which the goods purchased will be delivered to the subscriber. That is, it will indicate to the supplier whether the goods will have to be shipped and by which means, or whether the subscriber will withdraw the goods at

supplier's shop.

  A second RZL 30, also having a ring topology, is connected to the database 28 for sending the digital signals representing the video / audio presentations to a collective antenna television system 32. The transmission of a single video image requires approximately 30 to 50 kilobytes of information. Because a large number of bytes of digital information is required to represent the video or image portion of a presentation, the second RZL 30 is required because it accepts a greater amount of digital information at a faster rate. higher than the first RZL 18. To meet this requirement, the transmission medium of the second RZL 30 is a wideband support and, preferably, an optical fiber cable comprising a plurality of optical fibers having a wider bandwidth than the first RZL 18 which transmits several hundred thousand of

bits of information per second.

  A channel server 32 receives the subscriber control information from the first RZL 18 and the representative information of video presentations selected from the second RZL 30, for transmission at a leading end of the collective antenna television network 38 An interface 34 and an interface 36 respectively connect the channel server 32 to the first RZL 18 and the second RZL 30. The channel server 32 comprises a microprocessor, a multi-megabyte random access memory, a self-correction encoder errors and a modulator. The video, audio and control information received by the channel server 32 is converted into a high-speed digital stream and modulated, so that it is suitable for transmission over a cable television network. The channel server 32 also schedules the order in which the information is sent to the cable television network and performs error correction autocorrection to ensure the reliability of transmission over the television network.

by cable.

  Typically, a COL 11 will serve approximately 5,000 to 10,000 subscribers depending on its location. Each COL 11 is able to communicate with other LOCs by means of a gateway 40 which in turn communicates with a high-speed transmission medium such as a broadband terrestrial cable or a satellite.

  communications. The gateway 40 includes a microphone

  computer having a memory of at least several megabytes and is respectively connected to the first RZL 18 and second RZL 30 by an interface 42 and an interface 44. By communicating with other COL, the COL can request information for example, a presentation that is not in its database 28, and it can in turn respond to requests from other COLs. In a conventional cable television network, having one end 38 at the head of the CATV collective antenna television network, trunk cables 46 leave end 38 as the primary signal path. A multiplicity of nodes 48 is disposed along the junction cables 46. At each node 48, a branch amplifier 49 (shown in Figures 2, 3 and 4) is generally mounted to amplify the video / audio presentations and for directing, along a secondary cable 50, to the home of the subscriber 52. At each node 48 and in accordance with the present invention, there is arranged a presentation reader 54 whose output is constituted by at least one secondary cable 50. In fig. 1, eight possible secondary cables 50 are connected to the presentation reader, but only one of the secondary cables 50 is shown as being actually used. From a branch connection 56 along each secondary cable 50, a branch cable 58 extends to the home 52 of the subscriber to be connected to a television set 60. Each branch cable 58 is

typically a coaxial cable.

  According to the present invention, the presentation reader 54 is a device whose installation is external to cable television, having about the dimensions of a conventional antenna antenna television branch amplifier and generally having the same power and mounting requirements than a bypass amplifier. In general terms, the presentation reader is a frequency-agile broadband receiver with a high-speed data demodulator tuned by a narrow-band fixed frequency control channel. The role of the presentation reader 54 is to receive, from the end 38 at the head of the collective antenna television network, a digital bit stream stream representing the video / audio presentations, to convert these digital bit packets into video / video presentations. audio, and transmit particular video / audio presentations, on pre-assigned output channels, to subscribers who request them. Each presentation reader 54 processes only the digital bit packets, representative of video / audio presentations requested by subscribers, which

  are assigned to this presentation reader 54. That is,

  say that the digital bit packets representing the video / audio presentations requested by a subscriber are addressed to a specific presentation reader 54 which is assigned the task of processing the presentation

video / audio for the subscriber.

  From what is shown in FIG. 2, the presentation reader 54 comprises at least one and up to eight subscriber servers 62: The subscriber server 62 may be at the disposal of a single subscriber and installed at his home as a subscriber. subscriber device, but in the typical case, a small group of subscribers will share it according to criteria of use. Any individual subscriber of a predefined group may have access to a subscriber server 62 by calling the service number of COL 11 and subscribing. When a subscriber has seized the use of a subscriber server 62, no other subscriber of the same group can use the server

  of subscribers 62 until this first subscriber has completed.

  The number of simultaneous subscribers and users for which a presentation reader 54 has been installed depends on (1) the number of subscriber servers 62 present in the presentation reader 54, <2) average usage forecasts by the subscribers assigned to each subscriber server 62 and (3) the number of selectively assignable output channels to subscribers, which may be available to COL 11 for transmitting the presentations

  video / audio in the cable television network.

  The presentation reader shown in FIG. 2 comprises eight subscriber servers 62; however, it is contemplated in the context of the present invention that there may be or may not be more than one output channel frequency accessible by two or more subscriber servers. Typically, the presentation reader 54 will be installed near a branch amplifier 49 and will serve between one and eight simultaneous users, served by one to eight secondary cables 50. The number of secondary cables (or power cables) 50 powered 54 is determined by construction criteria that relate to (1) the number of homes served by the community cable television power cable in question, (2) the channel assignment of the television system by local collective antenna and (3) local installation considerations and

start-up of the public service.

  In addition to the subscriber servers 62, each presentation reader 54 also contains a subscriber server control unit 64 and a presentation reader converter 66. The choice of the configuration of a presentation reader 54 will depend on the service requirements of the area in which the reader of

Presentations 54 is installed.

  The presentation reader converter 66 is tuned to a fixed frequency narrowband control channel, so that it tuns itself to a broadband channel to receive the bit packets.

  representative digital video / audio presentations.

  In other words, the converter 66 receives tuning information on the narrowband control channel and, in response to this information, it agrees on the designated broadband channel which carries the digital bit stream stream. As a result of this self-tuning process, the presentation reader converter 66 selects the correct channel, demodulates the signal to form a digital train amenable to local processing, performs self-correction of errors and determines whether the bit packetized information in the digital stream it is monitoring is destined for a particular subscriber server 62, housed in the presentation reader 54. In essence, the converter 66 of the presentation player is a frequency-agile broadband receiver, with a high-speed data receiver tuned through a frequency control channel

fixed to narrow band.

  The output signal of the converter 66 of the presentation reader is transmitted to the subscriber server control unit 64, as shown in FIG. 2. The subscriber server control unit 64 is a splitter device which directs the signals from the converter 66 of the presentation reader to the appropriate subscriber server 62. That is, the subscriber server control unit 64 determines the particular subscriber server 62 that is designated to receive the information in the form of bit packets. This bit packet information includes video and audio bit packets representative of the video / audio presentation, as well as a script of the presentation. The presentation script determines when and during which time period the subscriber server 62 will transmit video and audio images representative of a particular video / audio presentation. The work of the subscriber server 62 includes performing a digital / analog conversion of the video / audio presentation, inserting graphical information that is made of ASCII characters, embedding background audio music, and transmission of video / audio presentations on assigned output channels, in NTSC format compatible, so that the subscriber who has made the request can watch them. The function of the presentation reader converter 66 is to locate and agree on the frequency band, in the collective antenna television spectrum, where the digital information stream is located, and to transform and control this information into their processing and, if necessary, their detail handling, to deliver video / audio presentations to subscribers who request it. This function of the converter 66 of the presentation reader will appear more clearly on reading

  the following description of its components.

  As shown in fig. 3, the converter 66 of the.

  Presentation player includes a fixed frequency receiver 68 which is tuned permanently to a predetermined narrowband control channel in the collective antenna television spectrum. This narrow-band control channel, for example 10 kHz or less, contains the information that the converter 66 needs to control the presentation reader 54. A fixed control channel receiver 68 transmits digitally encoded information to a demodulator 70 made with a very high degree of integration at a speed of about 9600 bits per second. At this speed, up to one hundred million destination addresses can be ordered, with command-driven error correction, presentation format variations, and a set of diagnostic commands. After the demodulator 70 has self-corrected the errors, it transmits the signal to a receiver control unit 72 which stores manipulation and processing commands including product presentation script instructions, video bitmap designations. audio, diagnostic reporting programs, and local screen savers

subscriber information.

  The frequency of the high-speed input channel is transmitted by the receiver control unit 72 to a frequency-agile broadband receiver 74. The receiver 74 is tuned to the channel designated by the unit 72 of FIG. receiver control. The signal of the designated channel is sent by the receiver 74 to a demodulator 76. The demodulator 76 converts the analog signal into a digital bit stream, performs an error self-correction, and then sends the received digital bit packets to the unit. 72 receiver control. In the receiver control unit 72, the digital bit packets for the presentation reader 54 are selected and transmitted to the control unit 64.

subscriber server.

  The subscriber server control unit 64 sends the digital bit packets of information to one of the subscriber servers 62 which is in the presentation reader 54. In accordance with the addressing information contained in the digital bit packet, each subscriber server 62 housed in a presentation reader 54 is responsible for processing the designated digital information bitstreams for subscribers assigned to that particular presentation reader. Referring to FIG. 4, the information bit packets transmitted from the subscriber server control unit 64 are received by a small central unit 78 in the subscriber server 62 and stored in a random access memory group 80 The CPU 78 determines which of the information bit packets is a script bit packet, and then uses the script bit packet to determine how the video and audio bit packets are to be combined with graphics information. real time to be reviewed by the subscriber. The script bit packets also define the fidelity and duration of the background and overlay audio message, as well as the situation on the screen and the duration of video images with accompanying visual text. In addition, the script bit packets define a series of video / audio sequences automatically passing to satisfy a particular request from a subscriber. In case of error detection during the preparation of a sequence of product presentations, the subscriber server control unit 64 will instead issue a replacement message from the local random access memory to communicate information. or some

instructions to the requesting user.

  From the CPU 78, the script bit packets are transmitted to a video expander 82 or to an audio expander 84, depending on whether they contain video or audio information. The video expander 82 includes graphics overlay means, as well as functions to reverse the process defined by a video compression algorithm. The audio expander 84 decompresses the audio bit packets and converts them in real time. The video and audio bit packets are also processed by a video processor 86 and an audio processor 88. After the video and audio information has been queued and expanded, they are used to modulate an antenna television channel. collective which can be selected by the subscriber, by means of an output modulator 90, frequency agile transmitter, which transmits to the subscriber

  applicant the assembled presentation in N.T.S.C.

  on the frequency assigned by the central unit 78, directed by the COL 11. Thus, it is through the presentation reader 54 that the requested video / audio presentations are transmitted on channels of

  pre-assigned output to requesting subscribers.

  The embodiment for illustrating the present invention has been described in detail with reference to the accompanying drawings, but it should be understood that the invention is not limited to this particular embodiment and that various changes or modifications may be made thereto. by the person skilled in the art, without thereby departing from the scope or the spirit of the invention.

Claims (17)

  1.- presentation reader in an interactive communication system, in which subscribers select from a multiplicity of video / audio presentations, these video / audio presentations being transmitted in the form of packets of digital information bits to at least a presentation reader, each of these digital bit packets being univocally addressed to the requesting subscriber, said presentation reader each comprising means (66) converters tuned to a channel, for monitoring a digital train of information containing said packets of digital bits representative of selected video / audio presentations and for detecting, for further processing, packets of digital bits uniquely addressed to predetermined ones of said requesting subscribers, control means <64) which receives said bit packets numerical addressed univocally and transmit each of these ts of bits to a pre-assigned subscriber server (62) according to its unambiguous address, and at least one subscriber server (62) which receives the uniquely addressed digital bit packets, converts them into analogically formatted video / audio presentations and transmits these presentations   video / audio to the requesting subscriber.   The presentation reader of claim 1, comprising no more than eight subscriber servers (62). 3. Presentation reader according to claim 1, wherein the converter means (66) are   tuned to a broadband channel.   The presentation player of claim 1, wherein said subscriber server (62) transmits the video / audio presentation on an output channel pre-assigned in N.T.S.C.   The presentation reader of claim 1, wherein said subscriber server (62) further comprises a central processing unit (78) for receiving and processing said uniquely addressed digital bit packets and for storing such packets of bits in   a random access memory (80).   The presentation reader of claim 1, wherein said digital bit packets include video bit packets, audio bit packets, and script bit packets that determine the manner in which the video and audio bit packets. are combined into a video / audio presentation. The presentation reader according to claim 1, wherein said converter means is tuned to said monitoring channel based on tuning information received from a control channel at   narrow band at pre-fixed frequency.   The presentation reader of claim 7, wherein the narrow-band control channel is kHz or less.   The presentation reader of claim 7, wherein said converter means further comprises a fixed control channel receiver (68). for   receive said narrow-band control channel.   The presentation reader of claim 9, wherein said fixed control channel receiver (68) transmits digitally encoded information to a demodulator (70) at a rate of about 9600 bits per second and the output signal of this demodulator is transmitted to a receiver control unit <72) which designates to a frequency agile broadband receiver <74) the monitoring channel.   The presentation reader of claim 1, wherein said monitoring channel is within   the frequency spectrum of cable television.   12. Presentation reader for receiving video / audio presentations selected by a subscriber of an interactive communication system, these video / audio presentations being transmitted in the form of packets of digital information bits, each of these packets of digital bits being univocally addressed to the calling subscriber, said presentation reader comprising channel-tuned converters means (66) for monitoring a digital information stream containing said digital bit packets representative of selected video / audio presentations and for detecting, for further processing, packets of digital bits uniquely addressed to predetermined subscribers of said requesting subscribers, control means (64) which receives said uniquely addressed digital bit packets and transmits each of said bit packets to a subscriber server (62) pre-assigned according to his address uniquely, and at least one subscriber server (62) which receives the uniquely addressed digital bit packets, converts them into analogically formatted video / audio presentations and transmits these video / audio presentations to said requesting subscriber.  13.- Device mounted in a cable television network for distributing to subscribers video / audio presentations selected by these subscribers, comprising means for receiving a digital binary packet of information through a medium of distribution, these digital bit packets being representative of video / audio presentations selected by said subscribers, means for converting these digital bit packets into analogically formatted video / audio presentations, and means for transmitting these analogically formatted video / audio presentations, on preassigned output channels to said requesting subscribers. 14.- Device according to claim 13, wherein said distribution support is a connection of   remote distribution of cable television.   The device of claim 13, wherein said video / audio presentations include still images.   16. The device according to claim 15, wherein said video / audio presentations comprise in   in addition to one or more audio messages.   17. The device according to claim 13, wherein said video / audio presentations comprise animated images.